The Orchestre national de jazz, known as the ONJ, is France's state-funded jazz orchestra. It was created in 1986 on the initiative of the culture minister Jack Lang and is run by a non-profit association, the AJON, which hands the baton to a new artistic director every few years. Each director builds the orchestra anew around a project of their own, so the ONJ has been a different band, with a different sound and repertoire, every time the post has changed hands. Over four decades it has recorded more than thirty albums and featured more than 200 soloists, and in 2009 and 2020 it won the Victoires du jazz.

The idea came from the Ministry of Culture's music and dance directorate under Maurice Fleuret, who in 1983 set up an advisory commission for jazz. In the summer of 1985 Lang announced a subsidised national orchestra meant to keep alive and renew the repertoire of the great jazz orchestras. Its first concert took place on February 3, 1986 at the Théâtre des Champs-Élysées in Paris, led by the saxophonist François Jeanneau after only a few weeks of rehearsal, with the pianist Martial Solal, the arranger Gil Evans and the saxophonist and clarinettist Michel Portal as invited guests. The 1986 band included the saxophonist Jean-Louis Chautemps and the guitarist Marc Ducret. It made its first album for Label Bleu that year, with the guitarist John Scofield guesting on one track, and a concert recorded at the Friedrichstadtpalast in East Berlin on June 29, 1986 came out on the East German Amiga label in 1987.

The next directors each turned the band toward their own tastes. The pianist Antoine Hervé led it from 1987 to 1989 (O.N.J. 87, African Dream), with the guitarist Nguyên Lê and the drummer André Ceccarelli among his players. The guitarist Claude Barthélemy followed from 1989 to 1991 (Claire, Jack-Line), and his successor, the pianist Denis Badault (1991 to 1994), moved the orchestra further from its institutional beginnings; his albums À plus tard, Monk Mingus Ellington and Bouquet final all came out on Label Bleu, and the vocalist Élise Caron sang in the band. Laurent Cugny, a pianist and arranger, directed from 1994 to 1997 and took the ONJ to Verve for Yesternow, In Tempo, Reminiscing and Merci, merci, merci; the trumpeter Flavio Boltro and the saxophonist Stefano Di Battista were in his lineup.

The bassist Didier Levallet (1997 to 2000) recorded ONJ Express, Séquences and Deep Feelings for Evidence, with the pianist Sophia Domancich and the trumpeter Harry Beckett in the band and the singer Jeanne Lee as a guest on the last. The Italian cellist Paolo Damiani, who directed from 2000 to 2002 with Jeanneau as co-director, made Charmediterranéen for ECM, with soloists including the saxophonist Javier Girotto, the trumpeter Médéric Collignon and the trombonist Gianluca Petrella. Barthélemy returned from 2002 to 2005 (Admirabelamour, La Fête de l'eau, and a 2004 tour of Canada released on DVD). The vibraphonist Franck Tortiller (2005 to 2008) had one of the orchestra's best sellers with Close to Heaven, a Led Zeppelin tribute that sold more than 10,000 copies, and followed it with Électrique.

In 2008 the bassist and producer Daniel Yvinec was named artistic director, a change of role as well as of person: rather than a bandleader who plays in the orchestra, he chose ten young instrumentalists he did not already know and commissioned repertoires for them. Around Robert Wyatt (Bee Jazz, 2009), built on the songs of the former Soft Machine drummer with guest singers, won the Victoires du jazz prize for the instrumental album of the year at the ceremony in Paris on September 1, 2009 and sold more than 15,000 copies. Shut Up and Dance (2010) is ten pieces written for the band by the American composer John Hollenbeck, one of which, "Falling Men", was nominated at the 2012 Grammy Awards for Best Instrumental Composition. Yvinec's term also produced Piazzolla! with the arranger Gil Goldstein, a tribute to Billie Holiday and a score for Eisenstein's Battleship Potemkin, five concerts in Morocco in June 2013 and a final concert in December 2013 on the repertoire of The Party.

The guitarist Olivier Benoit directed from January 2014 to the end of 2018. His Europa cycle gave one album to each of four capitals: Europa Paris (2014), Europa Berlin (2015), Europa Rome (2016) and Europa Oslo (2017), all on the orchestra's own ONJ Records label, and he commissioned the American drummer Mike Reed to write a Chicago programme. A box set marked the orchestra's thirtieth anniversary in 2018. The guitarist Frédéric Maurin took over in January 2019 with a rotating lineup, the first in the orchestra's history to field as many women as men. His programmes were Dancing in Your Head(s), a tribute to Ornette Coleman arranged by Fred Pallem with the saxophonist Tim Berne as guest, and Rituels, a collective work for orchestra and four voices (both 2020); Dracula (2021), the orchestra's first show for young audiences, issued as a book-disc; a 2021 revival at Radio France of André Hodeir's Anna Livia Plurabelle; and Ex Machina (2022, album 2023 on Pi Recordings), written with the American saxophonist Steve Lehman using real-time electronics developed at Ircam. In 2019 Maurin also founded the Orchestre des Jeunes de l'ONJ, in which young musicians replay earlier ONJ repertoires under a former director, and in 2022 an annual composition academy. His term closed in January 2025 with Jeux, a concert pairing seven ONJ soloists with seven from the Ensemble intercontemporain.

The flautist and composer Sylvaine Hélary was named artistic director in March 2024 for a four-year term, renewable for two, and began her project in 2025. Her first programme, With Carla, revisits the music of Carla Bley with arrangements by Hélary and the saxophonist Rémi Sciuto for seventeen soloists, and an album of it appeared in May 2026. A second programme, La Planète sauvage, is built on the 1973 animated film, and a third, L'Écho des oiseaux, is announced for 2027. The orchestra's own calendar lists With Carla dates from December 2026 to May 2027, and the Orchestre des Jeunes continues under the pianist Sophia Domancich on Levallet's repertoire.

There is no single ONJ style, because the orchestra is rebuilt for each director. The common thread is commissioned, composed repertoire for a flexible large ensemble rather than a standing big band playing a fixed book: Badault's programme of Thelonious Monk, Charles Mingus and Duke Ellington, Yvinec's Wyatt, Hollenbeck and Piazzolla programmes, Tortiller's rock-flavoured Led Zeppelin set, and Maurin's tributes to Coleman and Bley. Lineups range from ten players to more than twenty and often include voices, strings, accordion, electronics or guests from rock and chanson. AllMusic files the orchestra under avant-garde jazz and lists its styles as avant-garde jazz, modern composition, modern creative and progressive big band.